01/04/2010

01/04/2010• Start of the studies delayed due

to trip of RQD.A12 at 08:43 at the end of pre-cycling nQPS triggered but no signal observed above threshold.

• Injection started at ~12:00 for RF capture optimization. Due to the low longitudinal emittance delivered by the SPS the capture voltage could be decreased from 8 to 5 MV at injection

• Trim to new values implemented in the sequencer

01/04/2010• Preliminary tests of the chromaticity measurement by RF

frequency modulation

01/04/2010• Smooth ramp in preparation of

squeeze test• 15:00 Beam lost at flat-top due

to bad manipulation with the sequencer

• Finally ready to start the squeeze at 18:30

• No losses during the squeeze (except to over enthusiastic use of AC dipole)

01/04/2010• b* = 9 m• Tune and chromaticity OK

01/04/2010• b* = 9 m • Beta beating measurement

• Beam 2

• Beam 1 (lost 80 % of the beam during AC dipole excitation)

01/04/2010• b* = 7 m• Tune and chromaticity OK

01/04/2010• b* = 7 m• Beam 2

01/04/2010• b* = 5 m - Tune and chromaticity OK. Coupling increases to

~0.01

01/04/2010• b* = 5 m• Beam 2

01/04/2010• Coupling Beam 2• b*=9 m b*=5 m

01/04/2010• Important loss during the ramp beam unstable. Likely

chromaticity too low

01/04/2010• Today:

– 05:00 Ramp (without feedback) - OK– 06:37 – lost cryo (oil pump?) – beams dumped – access in PZ45 for CRYO intervention

– around 14:00 – recover from cryo– 09:00 Tune feedback / chromaticity measurement during the ramp– 14:00 Non linear chromaticity measurement and off-momentum beta

beating– 17:00-18:00 LHCb polarity change– Prepare fill for the night

01/04/2010• Saturday to Monday:

– 2 fills/day with an end of fill or beginning of fill study (2-3 hours)

• Beginning/End of fill study list in work– Working point in collision– Machine protection tests– Non-linear chromaticity measurement at flat-top– b3 correction checks